JP2003134589A - Speaker enclosure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker enclosure capable of effectively preventing damping caused by a reflected wave at the rear of a speaker unit without adversely affecting a high-band frequency component. SOLUTION: A speaker unit 20 is installed on one side of a speaker box 10. A drawncone unit 30 is installed on the side facing the one side. The drawncone unit 30 has a drawncone 31 and a cover 32. The drawncone 31 is formed of a domed thin plate raised toward the inside of the speaker box 10. The cover 32 is formed of a domed plate raised toward the outside of the speaker box 10 and is installed so as to cover the drawncone 31. A first closed housing X is formed by utilizing the inner surface of the speaker box 10, the speaker unit 20 and the drawncone 31. A second closed housing Y is formed between the drawncone 31 and the cover 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed speaker enclosure, and more particularly to a technique for effectively preventing reflected waves inside a closed room.

[0002]

2. Description of the Related Art As shown in FIG. 5, a general sealed speaker enclosure has a speaker unit 2 attached to a hole formed in one side surface of a rectangular parallelepiped speaker box 1 and hermetically sealed. In such a speaker box 1, in particular, a large-diameter speaker unit 2
When using, the problem of braking the speaker unit 2 arises. This is because a sound pressure wave generated on the back surface of the speaker unit 2 (indicated by an arrow pointing left in the figure) is reflected on a surface of the speaker box 1 behind the speaker unit 2 (indicated by an arrow pointing right in the figure). ), When it reaches the speaker unit 2 again, if the phase of the reflected wave and the phase of the speaker diaphragm are deviated, the diaphragm is damped by the reflected wave.

In order to deal with this, a method using a sound absorbing material such as glass wool or a porous material has been conventionally used. This is a method of absorbing a sound pressure wave generated on the back surface of the speaker unit 2 and preventing a reflected wave by disposing a sound absorbing material 3 in the speaker box 1 as shown in FIG. 6, for example. .

[0004]

By the way, as a countermeasure against the reflected wave in the conventional speaker enclosure as described above, a sound absorbing material which uniformly absorbs the sound pressure wave from the speaker unit is arranged. For this reason, the sound of the high frequency is also absorbed, which affects the sound heard by the user.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and the purpose thereof is to dampen the high frequency components by the reflected wave on the rear surface of the speaker unit. It is to provide a speaker enclosure that can effectively prevent

[0006]

In order to achieve the above-mentioned object, the invention according to claim 1 is such that the first closed chamber provided with a speaker unit and the acoustic output of the speaker unit, It is characterized by having a drone cone provided in the first closed chamber and a second closed chamber provided with the drone cone. In the invention according to claim 1 as described above, among the sound pressure waves generated from the speaker unit, the sound wave that interferes with the vibration of the bass speaker is absorbed by the vibration of the drone cone and is not reflected to the speaker unit side. Therefore, it is possible to prevent the reflected wave while not affecting the high frequency component, and to output the sound with stable characteristics. Further, since the airtightness is maintained by the first airtight chamber and the second airtight chamber, the characteristic as the airtight speaker is maintained.

According to a second aspect of the present invention, in the speaker enclosure according to the first aspect, the drone cone is
It is characterized in that it is attached toward the inside of the first closed chamber. In the invention described in claim 2 as described above,
Since the drone cone is attached toward the first closed chamber, it is possible to reduce the overall size and space.

The invention according to claim 3 is the speaker enclosure according to claim 1 or 2, wherein a plurality of the drone cones are provided. In the invention described in claim 3 as described above, reflected waves can be reliably prevented by the plurality of drone cones. This is particularly effective when the first closed chamber is large, such as a multi-way speaker having a plurality of speaker units or a horn load.

According to a fourth aspect of the invention, in the speaker enclosure according to any one of the first to third aspects,
At least one of the drone cones is provided at a position corresponding to the back surface of the speaker unit. In the invention according to claim 4 as described above, the drone cone is arranged at a position where it is likely to receive the sound pressure wave from the speaker unit, so the reflected wave can be most effectively prevented.

According to a fifth aspect of the present invention, in the loudspeaker enclosure according to any one of the first to fourth aspects, a conductor for guiding an acoustic output from the loudspeaker unit to the drone cone is provided in the first closed chamber. It is characterized in that a sound section is provided. In the invention described in claim 5 as described above, the sound pressure wave from the speaker unit is transmitted to and absorbed by the sound guiding section to the drone cone, so that the arrangement position of the drone cone and the degree of freedom of the enclosure shape are increased.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention (hereinafter referred to as "embodiments") will be specifically described with reference to the drawings. [1. Configuration of Embodiment] First, the configuration of the present embodiment will be described with reference to FIGS. 1 and 2. 1 is a vertical cross-sectional view of the present embodiment, and FIG. 2 is a diagram comparing the acoustic characteristics of the present embodiment and the conventional technique. That is, this embodiment is
As shown in FIG. 1, a rectangular parallelepiped speaker box 10 is provided.
A speaker unit 20 attached to one side surface of the speaker box 10 (hereinafter referred to as an attachment surface A), and a surface of the speaker box 10 opposed to the attachment surface A (hereinafter referred to as an attachment surface B). It is composed of the drone cone unit 30.

The speaker unit 20 is fixed in a circular hole 21 formed in the mounting surface A so that its diaphragm faces the front side and the coil side enters the speaker box 10. The drone cone unit 30 is the drone cone 3
1 and a cover 32, and is attached to the attachment surface B as follows. That is, the mounting surface B has a circular hole 22.
Is formed, and an annular frame 33 is fitted into this hole 22.

The drone cone 31 is the speaker box 1
It is a dome-shaped thin plate that rises toward the inside of 0,
Around the periphery of the frame 33 via the circumferential support 33a.
Is attached to. The word for this drone cone 31 is
The term widely refers to a vibrating member that exerts the operation described below, and includes what is called a diaphragm.
The cover 32 is a dome-shaped plate-like body that is bulged toward the outside of the speaker box 10.
Is attached to the frame 33 so as to cover the. The speaker box 10 has an inner surface and a speaker unit 2
0 and the drone cone 31 form a first sealed chamber X, and a second sealed chamber Y is formed between the drone cone 31 and the cover 32.

[2. Operation of Embodiment] The operation of the present embodiment as described above is as follows. That is, the sound pressure wave (indicated by a plurality of arc lines on the right side in the figure) generated on the back surface of the speaker unit 2 is absorbed by the vibration (displacement) of the drone cone 31 and is not reflected to the speaker unit 2 side. However, since the cover 32 forms the second closed chamber Y, the speaker box 10 is maintained in a closed state with respect to the surroundings. Therefore, the characteristics of the closed type speaker are not lost.

Further, since the vibration of the drone cone 31 is limited to the sound wave that disturbs the vibration of the bass speaker, such as a pressure wave having a sudden large amplitude, only unnecessary sound at a high frequency is absorbed. Is absorbed.
This will be described with reference to the graph of FIG. This Figure 2
Is a comparison between the present embodiment shown in FIG. 1 and the conventional speaker enclosure as shown in FIG. 6 by measuring the sound pressure on the back surface of the speaker unit, where the vertical axis represents the sound pressure and the horizontal axis represents the sound pressure. Indicates the frequency.

According to this measurement result, it is understood that in the prior art, the loudspeaker box 1 is excited by a large amount of energy in the low frequency range, and a standing wave is internally generated by the reflected wave even in the high frequency range. On the other hand, in the present embodiment, the sound in the speaker box 10 is diffused, and the standing wave in the vertical direction is particularly suppressed. In addition, since it has a double closed chamber structure having an air layer on the front surface, it has a high Q (quality factor) due to such standing waves and unnecessary vibration of the amplifier housing.
Unnecessary noise such as resonance sound having r) leaks out of the speaker box to a minimum.

[3. Effect of Embodiment] According to the present embodiment as described above, by effectively absorbing the pressure wave behind the speaker unit 2, braking by the reflected wave of the speaker unit 2 is prevented and the high frequency component is prevented. Since there is no effect on, the more stable sound output is possible.

Further, since the sound absorbing material used can be reduced, the manufacturing process can be simplified and the manufacturing cost can be reduced. Particularly, in the case of a speaker for bass, a sound absorbing material can be basically unnecessary.

Further, since the raised side of the drone cone 31 faces the inside of the first closed chamber X, there is no protrusion to the outside, and the protrusion of the cover 32 from the speaker box 10 can be suppressed, and the drone cone 31 can be downsized. The space can be reduced.

[4. Other Embodiments] The present invention is not limited to the above embodiments. For example, as shown in FIG. 3, a speaker box 10 having a relatively large size such as having a horn load for ensuring a low sound range is provided.
In this case, by providing a plurality of drone cone units 30, it is possible to more reliably prevent reflected waves. In such a case, it is desirable to arrange at least one of the drone cones 31 so as to be behind the speaker unit 20 in order to suppress reflected waves.
Further, in FIG. 3, the cover 32 includes a plurality of drone cones 31.
Each cover is provided individually, but one cover 32 may be provided so as to cover the plurality of drone cones 31.

The location of the drone cone is not limited to the back surface of the speaker box, but may be located on another side surface. In addition, inside or outside the speaker box, a sound guide part for guiding the sound output from the speaker unit is formed,
A drone cone unit may be arranged ahead of it. Although the shape of the sound guide portion is arbitrary, it may be tubular, for example. In this way, by changing the arrangement position of the drone cone, it becomes possible to accommodate enclosures of various shapes.

The material of the drone cone and the cover is not limited to a particular material. For example, the drone cone may be cone paper, ceramics, synthetic resin, wood, glass, metal, rubber, or any other vibrating body having characteristics close to the above acoustic characteristics. It may be formed using a material. A diaphragm similar to or different from the diaphragm of the speaker unit may be used. The cover may be synthetic resin, wood, metal, or any other material that can keep the enclosure sealed and prevent leakage of unwanted sound. It may be the same material as the speaker box or a different material. Good.

The shapes of the drone cone and the cover are also free, and are not limited to those illustrated in the above embodiment. For example, the drone cone may be a flat type. On the other hand, it is also possible to configure the cover as a flat shape or a shape close to a flat shape to form an enclosure having a small number of protruding portions as a whole. The shape and material of the speaker box and the speaker unit are not limited to a specific type. The attachment structure between the drone cone, the cover, and the speaker box may be any structure as long as it can ensure the airtightness. Furthermore, the speaker enclosure of the present invention can be applied to any type of indoor or outdoor type. For example, in FIG.
As shown in (a) and (b), it can be configured as a vehicle-mounted speaker enclosure.

[0024]

As described above, according to the present invention, it is possible to provide a speaker enclosure capable of effectively preventing the braking due to the reflected wave on the rear surface of the speaker unit without affecting the high frequency components. You can

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a configuration example of an embodiment of a speaker enclosure of the present invention.

FIG. 2 is an explanatory diagram showing a difference in acoustic characteristics between an embodiment of the present invention and a conventional technique.

FIG. 3 is a vertical cross-sectional view showing another embodiment of the present invention.

FIG. 4 is a plan view (a) and an AA vertical sectional view (b) showing another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view showing an example of a conventional speaker enclosure.

FIG. 6 is a vertical cross-sectional view showing an example of a conventional speaker enclosure incorporating a sound absorbing material.

[Explanation of symbols]

1, 10 ... Speaker box 2, 20 ... Speaker unit 3 ... Sound absorbing material 21, 22 ... holes 30 ... Drone cone unit 31 ... Dron Cone 32 ... Cover 33 ... Frame 33a ... Circular support A, B ... Mounting surface X, Y ... sealed room

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[Procedure amendment]

[Submission date] October 31, 2001 (2001.10.10.
31)

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (5)

[Claims] 1. A first closed chamber having a speaker unit, a drone cone provided in the first tight chamber so as to be driven by an acoustic output of the speaker unit, and a second drone having the drone cone. A speaker enclosure having a closed chamber. 2. The speaker enclosure according to claim 1, wherein the drone cone is attached toward the inside of the first closed chamber. 3. The speaker enclosure according to claim 1, wherein a plurality of the drone cones are provided. 4. At least one said drone cone comprises:
The speaker enclosure according to claim 1, wherein the speaker enclosure is provided at a position corresponding to the back surface of the speaker unit. 5. The sound guide part for guiding the acoustic output from the speaker unit to the drone cone is provided in the first closed chamber, according to any one of claims 1 to 4. The speaker enclosure described.